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1.
北京地区蝗虫种类研究及其垂直分布调查   总被引:3,自引:0,他引:3  
车晋滇  杨建国  胡彬 《昆虫知识》2006,43(2):254-257
经过2003~2004年对北京市平原区和山区的调查研究,初步发现北京市蝗虫有49种,隶属8科33属。由于植被、生态因素与环境条件和海拔高度的不同,蝗虫种类的垂直分布存在较明显的差异。对农林业为害较重的主要优势种有10种。  相似文献   

2.
Water availability is one of the key environmental factors that affect plant establishment and distribution. In many regions water availability will decline with climate change, exposing small seedlings to a greater likelihood of drought. In this study, 17 leaves, stem, root, and whole-plant traits of ten woody Mediterranean species were measured under favourable growing conditions and seedling drought survival was evaluated during a simulated dry-down episode. The aims of this study were: i) to assess drought survival of different species, ii) to analyse which functional traits predict drought survival time, and iii) to explain species distribution in the field, based on species drought survival and drought strategies. Drought survival time varied ten-fold across species, from 19 to 192 days. Across species, drought survival was positively related to the rooting depth per leaf area, i.e., the ability to acquire water from deeper soil layers while reducing transpiring leaf area. Drought survival time was negatively related to species ability to grow quickly, as indicated by high relative growth and net assimilation rates. Drought survival also explained species distribution in the field. It was found that species were sorted along a continuum, ranging between two contrasting species functional extremes based on functional traits and drought performance. One extreme consisted of acquisitive fast-growing deciduous species, with thin, soft metabolically active leaves, with high resource use and vulnerability to drought. The opposite extreme consisted of conservative slow-growing evergreen species with sclerophyllous leaves, deep roots, a low transpiring area, and low water use, resulting in high drought survival and drought tolerance. The results show that these drought strategies shape species distribution in this Mediterranean area.  相似文献   

3.
Aim Determining which traits predispose a species to become invasive is a fundamental question of invasion ecology, but traits affect invasiveness in concert with other factors that need to be controlled for. Here, we explore the relative effects of biological traits of plant species and their distributional characteristics in the native range on invasion success at two stages of invasion. Location Czech Republic (for native species); and the world (for alien species). Methods The source pool of 1218 species of seed plants native to Central Europe was derived from the flora of the Czech Republic, and their occurrence in 706 alien floras all over the world was recorded, distinguishing whether they were listed as an ‘alien’ or a ‘weed’ in the latest version of Randall’s ‘Global compendium of weeds’ database. The latter type of occurrence was considered to indicate species ability to invade and cause economic impact, i.e. a more advanced stage of invasion. Using the statistical technique of regression trees, we tested whether 19 biological traits and five distributional characteristics of the species in their native range can be used to predict species success in two stages of invasion. Results The probability of a species becoming alien outside its native distribution range is determined by the size of its native range, and its tolerance of a wide range of climates acquired in the region of origin. Biological traits play only an indirect role at this stage of invasion via determining the size of the native range. However, the ability of species to become a weed is determined not only by the above characteristics of native distribution, but also directly by biological traits (life form and strategy, early flowering, tall stature, generative reproduction, number of ploidy levels and opportunistic dispersal by a number of vectors). Species phylogenetic relatedness plays only a minor role; it is more important at the lowest taxonomic levels and at the later stage of invasion. Main conclusion The global success of Central European species as ‘weeds’ is determined by their distributional characteristics in the native ranges and by biological traits, but the relative importance of these determinants depends on the stage of invasion. Species which have large native ranges and are common within these ranges should be paid increased attention upon introductions, and the above biological traits should be taken into account in screening systems applied to evaluate deliberate introductions of alien plants to new regions.  相似文献   

4.
Species distribution models are valuable tools in studies of biogeography, ecology, and climate change and have been used to inform conservation and ecosystem management. However, species distribution models typically incorporate only climatic variables and species presence data. Model development or validation rarely considers functional components of species traits or other types of biological data. We implemented a species distribution model (Maxent) to predict global climate habitat suitability for Grass Carp (Ctenopharyngodon idella). We then tested the relationship between the degree of climate habitat suitability predicted by Maxent and the individual growth rates of both wild (N = 17) and stocked (N = 51) Grass Carp populations using correlation analysis. The Grass Carp Maxent model accurately reflected the global occurrence data (AUC = 0.904). Observations of Grass Carp growth rate covered six continents and ranged from 0.19 to 20.1 g day−1. Species distribution model predictions were correlated (r = 0.5, 95% CI (0.03, 0.79)) with observed growth rates for wild Grass Carp populations but were not correlated (r = −0.26, 95% CI (−0.5, 0.012)) with stocked populations. Further, a review of the literature indicates that the few studies for other species that have previously assessed the relationship between the degree of predicted climate habitat suitability and species functional traits have also discovered significant relationships. Thus, species distribution models may provide inferences beyond just where a species may occur, providing a useful tool to understand the linkage between species distributions and underlying biological mechanisms.  相似文献   

5.
The most common approach to predicting how species ranges and ecological functions will shift with climate change is to construct correlative species distribution models (SDMs). These models use a species’ climatic distribution to determine currently suitable areas for the species and project its potential distribution under future climate scenarios. A core, rarely tested, assumption of SDMs is that all populations will respond equivalently to climate. Few studies have examined this assumption, and those that have rarely dissect the reasons for intraspecific differences. Focusing on the arctic-alpine cushion plant Silene acaulis, we compared predictive accuracy from SDMs constructed using the species’ full global distribution with composite predictions from separate SDMs constructed using subpopulations defined either by genetic or habitat differences. This is one of the first studies to compare multiple ways of constructing intraspecific-level SDMs with a species-level SDM. We also examine the contested relationship between relative probability of occurrence and species performance or ecological function, testing if SDM output can predict individual performance (plant size) and biotic interactions (facilitation). We found that both genetic- and habitat-informed SDMs are considerably more accurate than a species-level SDM, and that the genetic model substantially differs from and outperforms the habitat model. While SDMs have been used to infer population performance and possibly even biotic interactions, in our system these relationships were extremely weak. Our results indicate that individual subpopulations may respond differently to climate, although we discuss and explore several alternative explanations for the superior performance of intraspecific-level SDMs. We emphasize the need to carefully examine how to best define intraspecific-level SDMs as well as how potential genetic, environmental, or sampling variation within species ranges can critically affect SDM predictions. We urge caution in inferring population performance or biotic interactions from SDM predictions, as these often-assumed relationships are not supported in our study.  相似文献   

6.
The vertical distribution of cultured Atlantic salmon larger than 1 kg was monitored by hydroacoustics in both a shallow (6 m) and a deep (20 m) cage. Surface light levels and fish distribution were registered for three periods throughout the year. The two fish groups were fed calculated rations twice a day. During the winter and spring (including vernal equinox), the fish were distributed at around 5 m depth in both cages when not feeding. Around summer solstice, the fish preferred deeper waters when not feeding. The light dependency of the vertical migration was pronounced, and indicates clearly that even a 20 m deep cage is not deep enough to meet the depth requirements of large Atlantic salmon during summer.  相似文献   

7.
探究功能性状沿着环境梯度如何变化一直以来是基于性状的群落生态学的核心问题之一。尽管功能性状存在种内和种间变异, 但种内变异沿环境梯度如何变化仍有待探究。本文以鼎湖山南亚热带常绿阔叶林1.44 ha塔吊样地内16个树种的2,820个个体为研究对象, 探究4种叶功能性状(比叶面积、叶干物质含量、叶厚度和叶面积)沿群落垂直层次的种内变异。首先, 利用随机效应线性模型量化塔吊样地内的种内变异和种间变异; 其次, 利用Kmeans函数将森林的垂直层次划分为灌木层、亚冠层和林冠层, 并通过构建回归模型探究叶功能性状在群落垂直层次中的种内变异格局。最后, 应用混合线性模型和单因素方差分析的方法探究叶功能性状沿垂直层次的种内变异是否具有物种依赖性。结果表明: 在局域群落中, 并非所有叶功能性状的种内变异都低于种间变异; 叶功能性状在不同垂直层次的种内变异格局存在显著差异, 且种内变异与垂直范围呈正相关; 叶功能性状的种内变异具有较强的物种依赖性, 因此树种差异相对于小环境解释了更多的性状变异; 此外, 不同叶功能性状的种内变异沿垂直层次的变化趋势并不一致。本研究发现种内变异对于物种共存具有重要作用。  相似文献   

8.
Galli L  Capurro M  Torti C 《ZooKeys》2011,(146):19-67
The Italian Protura were studied basing on 5103 specimens from 198 sampling areas, along with bibliographic data from 49 collecting sites. 17 out of the 20 Italian regions are covered. As a result, 40 species have been identified (belonging to 8 genera and 4 families), 6 of which are new records for the Italian fauna.A key to the Italian species is reported, followed by a series of distribution maps and brief remarks for some of them. A preliminary biogeographical overview allowed us to delineate the chorological categories of these species, 10 of which are actually known only in Italy. The comparison with the species richness known for some best studied Central and Eastern European Countries leads us to speculate that widening our research, Italian Protura check-list will be much implemented.  相似文献   

9.
阿勒泰山蝴蝶种类调查及其垂直分布的研究   总被引:10,自引:0,他引:10  
对阿勒泰山南坡中国境内的蝴蝶进行了采集调查,共鉴定整理出7科、61属、100余种。其中凤蝶科1属1种,绢蝶科1属6种,粉蝶科8属22种,眼蝶科16属23种,蛱蝶科16属32种,灰蝶科12属15种,弄蝶科7属10种。分析了这些种类的垂直分布特点,将其划分为4个垂直分布带,即低山半荒漠带、山地灌木草地带、山地森林草原带和亚高山草原-草甸草原-高山垫状植被带。  相似文献   

10.
库车种子植物区系垂直分布格局分析   总被引:1,自引:0,他引:1  
该研究通过野外植被调查及相关文献资料查阅,探讨了库车山区种子植物区系的垂直分布格局特征及其对海拔变化的响应。结果表明:该区种子植物约有78科376属960种。其中,裸子植物3科3属9种,被子植物75科373属951种。植物科、属、种总数随着海拔的升高呈现先增加后降低的单峰分布结构。其中科总数在海拔1 600~1 800 m处为最高峰,属总数在海拔1 800~1 900 m处呈现最高峰;物种总数在海拔1 900~2 000 m处呈现最高峰,有478种(隶属59科,230属)。种子植物区系地理成分分析中,库车山区植物区系垂直海拔梯度上不管是科级水平还是属级水平种类成分都以温带分布型占优势。在垂直分布梯度上,温带分布科最高点出现在海拔1 800~1 900 m(含20科),从海拔2 800~2 900 m开始,随着海拔梯度升高呈现下降趋势,到海拔3 600~3 700 m时为最低点(含6科);温带分布属峰值出现在海拔1 900~2 000 m,随着海拔的升高呈现下降趋势。该研究结果对该区植物种质资源和生态系统多样性,植物资源的引种驯化、栽培和合理利用具有重要意义。  相似文献   

11.
Aim Although urban areas only occupy c. 2.8% of the earth's land surface, urbanization threatens biodiversity as areas of high human population density often coincide with high biodiversity. Therefore, nature conservation should concentrate on both remote areas and densely populated regions. Protecting rare plant species in rural and urban areas can contribute to the protection of biodiversity. We therefore need to understand why species are rare. Studies on causes of rarity often concentrate on either plant traits or extrinsic threats (such as habitat fragmentation or nitrogen enrichment). However, there are only a few studies that combine traits and extrinsic threats, although such analyses might clarify causes of rarity. We assessed how the affinity of vascular plant species to urban land use (‘urbanity’) interacts with plant traits in determining species frequency. Location Germany, resolution c. 12 km × 11 km. Methods Species with a low frequency may be rare because they occur in rare habitats or because of other reasons, although their habitat is frequent. Therefore, we calculated the frequency of species corrected for habitat frequency, i.e. relative species frequency. We explained relative species frequency by the interactions of species traits and species affinity to urban land use using generalized linear models. Simultaneous autoregressive error models controlled for phylogenetic relationships of species. Results Relative species frequency depends on species affinity to urban land use, independent of the different interactions between traits and urbanity used as predictors. The higher the urbanity the higher is species frequency. Urbanity interacts with species preferences towards temperature and soil acidity. Moreover, dispersal, nitrogen preferences and origin explain relative species frequency, amongst others. Main conclusions Many rare species, especially those preferring cool or acidic habitats might already have disappeared from urban areas. Analyses that combine species traits and environmental effects can explain the causes of rarity and help to derive better conservation strategies.  相似文献   

12.
植物功能性状能够反映植物对环境变化的响应, 从而影响生态系统功能。叶片是植物功能性状的重要研究对象, 但随着树冠垂直高度的增加, 植物叶片功能性状的变化规律仍不清楚。为了更好地解释植物对所处环境的响应机制, 本研究以鼎湖山南亚热带常绿阔叶林6个优势树种为研究对象, 对这些树种不同冠层高度的叶片比叶面积(SLA)、叶绿素相对含量(SPAD)、叶干物质含量(LDMC)、叶片碳含量(LCC)、叶片氮含量(LNC)、叶片磷含量(LPC)、叶片氮磷比(N : P)、等效水厚度(EWT)、氮平衡指数(NBI)、类黄酮含量(FLAV)共10个功能性状指标进行比较分析。结果表明: (1)随树冠垂直高度的增加, 叶干物质含量、类黄酮含量、等效水厚度和叶片磷含量呈增加趋势, 比叶面积和氮平衡指数呈减小趋势; 在冠层垂直方向上, 类黄酮含量与氮平衡指数、比叶面积与等效水厚度呈极显著负相关, 叶片氮含量与叶片磷含量呈极显著正相关。(2)不同树种叶片功能性状差异显著, 可能受植物自身特性和群落树种演替进程的影响。(3)叶片功能性状的种内差异沿垂直层次呈现不同的变化趋势。其中, 67%的树种的类黄酮含量随树冠垂直高度增加而显著增加, 67%的树种的氮平衡指数随树冠垂直高度增加而显著减小。南亚热带常绿阔叶林不同树种叶片功能性状随树冠垂直高度增加产生的变化, 反映了植物对光环境的适应以及对水资源和能量利用的不同策略。  相似文献   

13.
物种分布模型(SDMs)通过量化物种分布和环境变量之间的关系,并将其外推到未知的景观单元,模拟、预测地理空间中生物的潜在分布,是生态学、生物地理学、保护生物学等研究领域的重要工具.然而,目前物种分布模型主要采用非生物因素作为预测变量,由于数据量化和建模表达困难,生物因素特别是种间作用在物种分布模型中常被忽略,将种间作用...  相似文献   

14.
云南高黎贡山具有多样化的生态系统和生物资源。为探清该地区绿僵菌属(Metarhizium)真菌的物种多样性及其不同海拔的垂直分布特征, 沿海拔梯度(600-3,800 m)在7种典型植被类型(I: 干热河谷; II: 季风常绿阔叶林; III: 暖性针叶林; IV: 中山暖性常绿阔叶林; V: 山地苔藓矮林; VI: 寒温性灌丛或草甸; VII: 流石滩稀疏植被)中调查绿僵菌资源。从生境土壤中分离菌株, 通过多基因(nrSSUnrLSUEF-1αRPB1RPB2)系统发育分析进行物种鉴定。结果表明, 高黎贡山绿僵菌物种资源丰富, 获得的161株菌株分属于12个物种(Metarhizium rileyi, M. viridulum, M. lepidiotae, M. brunneum, M. pingshaense, M. anisopliae, M. robertsii, M. guizhouense, M. indigoticum, M. pemphigi, M. campsosterniMetacordyceps neogunnii), 其中M. indigoticum为中国新记录种, M. anisopliae complex中的物种(8种)较集中; 同时还采集到了绿僵菌的近缘属Nigelia属物种N. martiale。高黎贡山绿僵菌广泛分布于除类型VII (海拔3,600-3,800 m)外的6种植被类型(海拔600-3,400 m)中。中低海拔植被类型(I-IV)中菌株数量较多(≥23株)、物种多样性较高(4-9种), 而高海拔植被类型(V-VI)中菌株数量较少(2-8株)、物种较单一(1-2种)。中海拔的常绿阔叶林中绿僵菌资源最丰富, 其中季风常绿阔叶林(植被类型II)中的菌株数量(52株, 占总数的32.3%)和物种数(9种)最多; 中山湿性常绿阔叶林(植被类型IV)为其次(47株, 占总数的29.2%; 7种)。高黎贡山绿僵菌优势种现象明显, M. brunneum为最优势物种, 其菌株数占总数的46.6%, 在生境条件差异很大的6种植被类型(I-VI)中都存在, 说明该物种生态适应能力最强。  相似文献   

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Distribution patterns along a slope and vertical root distribution were compared among seven major woody species in a secondary forest of the warm-temperate zone in central Japan in relation to differences in soil moisture profiles through a growing season among different positions along the slope. Pinus densiflora, Juniperus rigida, Ilex pedunculosa and Lyonia ovalifolia, growing mostly on the upper part of the slope with shallow soil depth had shallower roots. Quercus serrata and Quercus glauca, occurring mostly on the lower slope with deep soil showed deeper rooting. Styrax japonica, mainly restricted to the foot slope, had shallower roots in spite of growing on the deepest soil. These relations can be explained by the soil moisture profile under drought at each position on the slope. On the upper part of the slope and the foot slope, deep rooting brings little advantage in water uptake from the soil due to the total drying of the soil and no period of drying even in the shallow soil, respectively. However, deep rooting is useful on the lower slope where only the deep soil layer keeps moist. This was supported by better diameter growth of a deep-rooting species on deeper soil sites than on shallower soil sites, although a shallow-rooting species showed little difference between them.  相似文献   

18.
陈孟晨  张景光  冯丽  滕嘉玲 《生态学报》2017,37(22):7614-7623
采用野外随机取样和室内萌发试验相结合的方法,对沙坡头人工植被区的藓类结皮、地衣结皮和裸沙覆盖区土壤种子库的组成及垂直分布特征进行了研究。结果表明:1)人工植被区土壤种子库的物种组成简单,以1年生草本为主,相较于裸沙,两种生物结皮的存在显著增加了土壤种子库的密度(P0.01),但降低了土壤种子库的物种多样性及其与地上植被的相似性;2)两种生物结皮覆盖区土壤种子库的总密度虽无显著差异,但在0—2 cm土层中,地衣结皮土壤种子库的密度显著高于藓类结皮(P0.05),而在2—5 cm和5—10 cm土层中,藓类结皮土壤种子库的密度高于地衣结皮,但差异不显著;3)不同生物结皮覆盖区土壤种子库的垂直分布特征存在差异,藓类结皮覆盖土壤中有活力的种子主要分布在0—5 cm土层中,而地衣结皮和裸沙覆盖土壤中有活力的种子主要分布在0—2 cm土层中,且随着深度的增加,土壤中有活力的种子急剧减少。该研究表明,相较于裸沙,生物结皮的存在不仅增加了土壤种子库的大小,还改变了土壤种子库的垂直分布格局。生物结皮层下仍有相当比例有活力的小种子,这些种子欠缺萌发条件,对地上植被的贡献作用较小,但它们的存在对荒漠生态系统健康及可持续发展具有重要意义。  相似文献   

19.
散孔材与环孔材树种枝干、叶水力学特性的比较研究   总被引:4,自引:0,他引:4  
左力翔  李俊辉  李秧秧  赵丽敏 《生态学报》2012,32(16):5087-5094
为揭示散孔材与环孔材树种树木水分生理特性的差异,选取了常见的3种散孔材落叶树种(毛白杨、法国梧桐和樱花)和3种环孔材落叶树种(刺槐、合欢和白蜡),研究了其枝干与叶水力学性质的差异及其协调性。结果表明:3种环孔材树种枝干横截面积基础上的最大比导水率(Ks-max)大于3种散孔材树种,但其木质部对空穴化的脆弱性(P50branch)高于散孔材树种,6种树木枝干的水分传输能力和抵抗空穴化能力之间存在一种相互制约的权衡关系。3种散孔材与3种环孔材树种的叶最大水力导度(Kl-max)和水力脆弱性(P50leaf)并无显著差异;对于3种散孔材树种,叶的水力脆弱性要高于枝干,但对3种环孔材树种而言,枝干的水力脆弱性要高于叶。6种树木枝干和叶的水力学性质(Kmax、P50)之间并无相关关系。这些结果表明:散孔材与环孔材树种的枝干水力学特性有明显差异,但叶水力学特性无差异;枝干与叶水力学性质之间是相互独立的。  相似文献   

20.
南岳蝶类区系构成及垂直分布   总被引:7,自引:0,他引:7  
朱巽 《昆虫知识》2004,41(1):64-69
通过调查发现 ,南岳共有 1 1 7种蝶类昆虫。区系分析结果表明 ,南岳蝶类以东洋成分为主 ;南岳蝶类的垂直分布从山麓到山顶 ,随着海拔的升高 ,东洋种类递减 ,古北成分逐渐增多 ,尤以海拔 85 0m以上更加明显 ;在海拔 1 2 5 0m以上 ,东洋界种被古北及古北跨区种所替代。  相似文献   

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